The Associated PressPresident Barack Obama speaks at a campaign stop for Democratic Senate candidate Martha Coakley at Northeastern University in Boston.

By David Weigel, Slate

Ohio is where Mittmentum goes to curl up and die. It was true two weeks ago. It was a true one week ago. It's true now, as the new Quinnipiac poll gives Barack Obama a 50-45 lead in the state, unchanged from the week before. Since Mitt Romney's surge after the first presidential debate, only one poll—Rasmussen—has given him a lead in Ohio.

• Obama's lead with with women is 17 points; Romney's lead with men is 5 points.

• By a 10-point margin, voters say the national economy is improving. By a 35-point margin they say the same of Ohio's economy. And 63 percent give "a lot" or "some" credit to the Obama administration.*

• Sen. Sherrod Brown leads Republican Josh Mandel by 9 points. If this race is the "control," then Quinnipiac is better for Democrats than most other surveys—most of which find Brown leading but Mandel within 5.

It's worse for Obama in two other swing states. Quinnipiac was a bit of an outlier in Florida, seeing a 9-point Obama lead before the debates; it's down to 1. Virginia has moved from a 5-point race to a 2-point race. But if Obama wins either one of those, and no blue state falls away, he wins the election. And Quinnipiac doesn't see any historical blue state slipping away.

"We haven't bothered with Pennsylvania in these last polls," says Maurice Carroll, director of the polling institute. "It's in the bag for Obama."

That's a somewhat bold position, given that Quinnipiac's last Pennsylvania survey gave Obama only a 4-point lead. But nonpartisan polling groups have found basically the same story—Mitt Romney has not gained the territory he needs in eastern Pennsylvania in order to win the election. He goes on the air today in Philly, just as Barack Obama takes over the news cycle there with a visit to New Jersey's storm-battered towns.